A243388 Number of length n+3 0..7 arrays with no four elements in a row with pattern abba (with a!=b) and new values 0..7 introduced in 0..7 order

14, 46, 174, 737, 3435, 17402, 94907, 552660, 3409915, 22122613, 149763921, 1050072965, 7573195764, 55841366002, 418835322674, 3182422956259, 24417445081110, 188710025928915, 1466319454136469, 11439104238553624

Offset

1,1

Comments

Column 7 of A243389

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 29*a(n-1) -349*a(n-2) +2287*a(n-3) -9065*a(n-4) +23201*a(n-5) -41175*a(n-6) +55373*a(n-7) -60041*a(n-8) +53229*a(n-9) -39663*a(n-10) +25113*a(n-11) -13424*a(n-12) +6232*a(n-13) -2386*a(n-14) +806*a(n-15) -209*a(n-16) +49*a(n-17) -7*a(n-18) +a(n-19)

Example

Some solutions for n=3
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....1....0....1....0....1....1....1....1....1....1....1
..2....2....1....1....2....2....1....2....0....1....0....0....0....2....0....2
..2....1....1....2....3....0....0....1....1....2....2....1....2....1....2....2
..3....2....1....2....4....0....2....3....2....3....3....0....1....2....0....0
..0....1....2....0....3....0....3....4....0....4....1....1....0....3....1....0

Crossrefs

Sequence in context: A242580 A243386 A243387 * A242581 A242582 A242583

Adjacent sequences: A243385 A243386 A243387 * A243389 A243390 A243391

Keyword

nonn

Author

R. H. Hardin, Jun 04 2014

Status

approved